Atopic dermatitis can be acute or chronic, but therapy is commonly sought for patients reporting chronic pruritic inflammation of the dermis and epidermis. Dermatitis is thought to be due to a type I (IgE-mediated) hypersensitivity reaction which leads to inflammation, characterized by the presence of oedema in the dermal spaces (spongiosis).
These reactions occur as the result of the release of vasoactive substances from mast cells and basophils. The result is a xerosis (dry skin), rash, and pruritus.
For further information see: dermatitis.
Type I hypersensitivity reactions are mediated by:
Extra info: Once mast cells bind IgE, they degranulate and release mediators of inflammatory reactions.